Motability is a leasing scheme, and for complicated reasons the manufacturers (especially Stellantis) are offering cheap lease deals.

In the case of Stellantis I believe this is driven by "compliance" requirements - the need to sell a certain percentage of EVs to avoid being fined by the EU. So they're not especially great EVs, but once they go to the lease firm they're counted as "sold". Someone may take a loss on the depreciation later, but not the driver.

A special consideration for Motability is that PIP recipients aren't allowed to save up for anything, so whatever vehicle they have has to be on finance.